The Experts below are selected from a list of 68817 Experts worldwide ranked by ideXlab platform
Zhangxin Chen - One of the best experts on this subject based on the ideXlab platform.
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deTermination of mass transfer parameters in solvent based oil recovery techniques using a non equilibrium boundary condition at the interface
Fuel, 2014Co-Authors: Reza S Etminan, Brij B Maini, Zhangxin ChenAbstract:Abstract Having a reliable estimate of gaseous-solvents molecular diffusion Coefficients in heavy oil and bitumen is a requisite for analysis and design of gas injection and solvent-based recovery techniques. Nevertheless, diffusion Coefficient is not measured accurately unless all other contributing mass transfer parameters are considered, included in the modeling, and estimated correctly. These other parameters are gas solubility and interface resistance, of which the latter is represented by mass transfer Coefficient Term. In this work, an analytical model is introduced in conjunction with an inverse technique to obtain these three abovementioned parameters using a single pressure decay data set. Sensitivity Coefficient analysis is applied as an additional practical evaluation tool to display the sensitivity of the measured pressure to each of the unknown parameters. Characterization of the interface resistance as a physical phenomenon which hinders the molecular diffusion of gas through the interface and complicates the modeling is further investigated in this work. Incipient asphaltene precipitation in heptane–toluene–asphaltene mixture was chosen as a potential phenomenon which alters the interfacial resistance. It is shown that our proposed inverse analysis locates the unknown parameters correctly when history matching per se is not disclosing all the sufficient information for accurate parameter estimation.
C.c. Hong - One of the best experts on this subject based on the ideXlab platform.
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Free Vibration Frequency of Thick FGM Circular Cylindrical Shells with Simply Homogeneous Equation by Using TSDT
Advances in Technology Innovation, 2020Co-Authors: C.c. HongAbstract:The objective of this study is to provide the frequency solutions of free vibration in thick FGM circular cylindrical shells by mainly considering both shear correction Coefficient and nonlinear Coefficient Term. This paper investigates the effects of third-order shear deformation theory (TSDT) and the varied shear correction Coefficient on the free vibration of thick functionally graded material (FGM), the circular cylindrical shells with simply homogeneous equation under thermal environment. The approach of derivations are given as follows, the varied value of shear correction Coefficient is included in the simple homogeneous equation. The nonlinear Term of displacement field of TSDT is also included to derive the simply homogeneous equation, some reasonable simplifications in the elements of homogeneous matrix under free vibration of thick FGM circular cylindrical shells are assumed, thus, the natural frequency can be found. Three parameters effect on the frequency of thick FGM circular cylindrical shells are computed and investigated, they are nonlinear Coefficient c1 Term, environment temperature and power law index. There are some main conclusions obtained, generally the natural frequency results are in decreasing value with the mode shape numbers for the thicker circular cylindrical shells. The values of natural frequencies are also affected by the nonlinear Coefficient Term.
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Free vibration frequency of thick FGM spherical shells with simply homogeneous equation by using TSDT
Journal of the Brazilian Society of Mechanical Sciences and Engineering, 2020Co-Authors: C.c. HongAbstract:The effects of third-order shear deformation theory (TSDT) and varied shear correction Coefficient on the free vibration frequency of thick functionally graded material (FGM) spherical shells are investigated with simply homogeneous equation under thermal environment. The nonlinear Coefficient Term of displacement field of TSDT is included to derive the simply homogeneous equation with the assumed reasonable simplifications in the elements of homogeneous matrix under free vibration of thick FGM spherical shells. The deTerminant of the Coefficient matrix in dynamic equilibrium differential equations under free vibration can be represented into the simply five-degree polynomial equation; thus, the natural frequency can be obtained. For the preliminary FGM spherical shell study, the effects of nonlinear Coefficient Term and meridional angle on the varied shear correction Coefficient calculation are not considered. The calculated values of shear correction Coefficient are increasing with the increase in power law index. Three parametric effects of nonlinear Coefficient Term, environment temperature and power law index on the frequency of thick FGM spherical shells are computed and investigated for a given meridional angle in the spherical shells. Data in underestimated or overestimated are also investigated in the frequency parameters under free vibration with and without the effects of nonlinear Coefficient Term, respectively.
Reza S Etminan - One of the best experts on this subject based on the ideXlab platform.
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deTermination of mass transfer parameters in solvent based oil recovery techniques using a non equilibrium boundary condition at the interface
Fuel, 2014Co-Authors: Reza S Etminan, Brij B Maini, Zhangxin ChenAbstract:Abstract Having a reliable estimate of gaseous-solvents molecular diffusion Coefficients in heavy oil and bitumen is a requisite for analysis and design of gas injection and solvent-based recovery techniques. Nevertheless, diffusion Coefficient is not measured accurately unless all other contributing mass transfer parameters are considered, included in the modeling, and estimated correctly. These other parameters are gas solubility and interface resistance, of which the latter is represented by mass transfer Coefficient Term. In this work, an analytical model is introduced in conjunction with an inverse technique to obtain these three abovementioned parameters using a single pressure decay data set. Sensitivity Coefficient analysis is applied as an additional practical evaluation tool to display the sensitivity of the measured pressure to each of the unknown parameters. Characterization of the interface resistance as a physical phenomenon which hinders the molecular diffusion of gas through the interface and complicates the modeling is further investigated in this work. Incipient asphaltene precipitation in heptane–toluene–asphaltene mixture was chosen as a potential phenomenon which alters the interfacial resistance. It is shown that our proposed inverse analysis locates the unknown parameters correctly when history matching per se is not disclosing all the sufficient information for accurate parameter estimation.
Ranga Vemuri - One of the best experts on this subject based on the ideXlab platform.
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VLSI Design - Efficient Symbolic Sensitivity based Parasitic-Inclusive Optimization in Layout Aware Analog Circuit Synthesis
20th International Conference on VLSI Design held jointly with 6th International Conference on Embedded Systems (VLSID'07), 2007Co-Authors: Huiying Yang, Ranga VemuriAbstract:High-performance circuit optimization and synthesis should consider parasitic effects. This paper introduces techniques for parasitic estimation and fast parasitic optimization based on symbolic sensitivity analysis. An effective framework to incorporate parasitic modeling and optimization is presented in order to account for parasitic effects during synthesis. In this paper we primarily focus on using efficient symbolic sensitivity analysis based on element-Coefficient diagrams (ECD) to evaluate the dominant parasitic effects so as to eliminate insignificant parasitics. An ECD is the cancellation-free and per-Coefficient Term generation version of deTerminant decision diagrams (DDDs). In this paper, parasitic-aware analog circuit synthesis methodology is proposed. The accuracy and efficiency of the parasitic-inclusive optimization have been demonstrated
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ASP-DAC - Efficient symbolic sensitivity analysis of analog circuits using element-Coefficient diagrams
Proceedings of the 2005 conference on Asia South Pacific design automation - ASP-DAC '05, 2005Co-Authors: Huiying Yang, Ranga Vemuri, Mukesh Ranjan, Wim Verhaegen, Mengmeng Ding, G. GielenAbstract:This paper presents a new method to perform efficient-first-order symbolic sensitivity analysis of analog circuits by direct differentiation of symbolic expressions stored as element-Coefficient diagrams (ECDs). An ECD is a compact graphical representation of a symbolic transfer function. It is the cancellation-free and per-Coefficient Term generation version of deTerminant decision diagrams (DDDs). The symbolic sensitivity equations obtained from ECDs are stored as a sensitivity-ECDs (SECDs) and can be evaluated extremely fast as it inherits the properties of ECDs. The proposed methodology has been applied to the calculation of sensitivities of four benchmark circuits and it has been demonstrated to be as accurate and more efficient than numerical sensitivity analysis done by SPECTRE.
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ISVLSI - Fast analog circuit synthesis using multiparameter sensitivity analysis based on element-Coefficient diagrams
IEEE Computer Society Annual Symposium on VLSI: New Frontiers in VLSI Design (ISVLSI'05), 1Co-Authors: Huiying Yang, A. Agarwal, Ranga VemuriAbstract:This paper presents a new method to perform efficient analog circuit synthesis by using accurate multiparameter sensitivity analysis based on element-Coefficient diagrams (ECDs). An ECD is the cancellation-free and per-Coefficient Term generation version of deTerminant decision diagrams (DDDs). The techniques based on DDD are the fastest symbolic analysis algorithms reported so far in literature. The symbolic multiparameter sensitivity equations obtained from ECDs can be evaluated so as to tune the parameters in analog synthesis process efficiently. The proposed methodology has been applied for the synthesis of a two stage opamp circuit. The experimental results demonstrate that the speed and convergence of analog synthesis are improved significantly.
Huiying Yang - One of the best experts on this subject based on the ideXlab platform.
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VLSI Design - Efficient Symbolic Sensitivity based Parasitic-Inclusive Optimization in Layout Aware Analog Circuit Synthesis
20th International Conference on VLSI Design held jointly with 6th International Conference on Embedded Systems (VLSID'07), 2007Co-Authors: Huiying Yang, Ranga VemuriAbstract:High-performance circuit optimization and synthesis should consider parasitic effects. This paper introduces techniques for parasitic estimation and fast parasitic optimization based on symbolic sensitivity analysis. An effective framework to incorporate parasitic modeling and optimization is presented in order to account for parasitic effects during synthesis. In this paper we primarily focus on using efficient symbolic sensitivity analysis based on element-Coefficient diagrams (ECD) to evaluate the dominant parasitic effects so as to eliminate insignificant parasitics. An ECD is the cancellation-free and per-Coefficient Term generation version of deTerminant decision diagrams (DDDs). In this paper, parasitic-aware analog circuit synthesis methodology is proposed. The accuracy and efficiency of the parasitic-inclusive optimization have been demonstrated
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ASP-DAC - Efficient symbolic sensitivity analysis of analog circuits using element-Coefficient diagrams
Proceedings of the 2005 conference on Asia South Pacific design automation - ASP-DAC '05, 2005Co-Authors: Huiying Yang, Ranga Vemuri, Mukesh Ranjan, Wim Verhaegen, Mengmeng Ding, G. GielenAbstract:This paper presents a new method to perform efficient-first-order symbolic sensitivity analysis of analog circuits by direct differentiation of symbolic expressions stored as element-Coefficient diagrams (ECDs). An ECD is a compact graphical representation of a symbolic transfer function. It is the cancellation-free and per-Coefficient Term generation version of deTerminant decision diagrams (DDDs). The symbolic sensitivity equations obtained from ECDs are stored as a sensitivity-ECDs (SECDs) and can be evaluated extremely fast as it inherits the properties of ECDs. The proposed methodology has been applied to the calculation of sensitivities of four benchmark circuits and it has been demonstrated to be as accurate and more efficient than numerical sensitivity analysis done by SPECTRE.
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ISVLSI - Fast analog circuit synthesis using multiparameter sensitivity analysis based on element-Coefficient diagrams
IEEE Computer Society Annual Symposium on VLSI: New Frontiers in VLSI Design (ISVLSI'05), 1Co-Authors: Huiying Yang, A. Agarwal, Ranga VemuriAbstract:This paper presents a new method to perform efficient analog circuit synthesis by using accurate multiparameter sensitivity analysis based on element-Coefficient diagrams (ECDs). An ECD is the cancellation-free and per-Coefficient Term generation version of deTerminant decision diagrams (DDDs). The techniques based on DDD are the fastest symbolic analysis algorithms reported so far in literature. The symbolic multiparameter sensitivity equations obtained from ECDs can be evaluated so as to tune the parameters in analog synthesis process efficiently. The proposed methodology has been applied for the synthesis of a two stage opamp circuit. The experimental results demonstrate that the speed and convergence of analog synthesis are improved significantly.